Rollers for pickling baths



July 10, 1962 B. e. BIRKIN ROLLERS FOR PICKLING BATHS 3 Sheets-Sheet 1 Filed Jan. 13, 1960 July 10, 1962 B. e. BIRKIN 3,042,995

ROLLERS FOR PICKLING BATHS Filed Jan. 13, 1960 3 Sheets-Sheet 2 July 10, 1962 B. e. BIRKIN ROLLERS FOR PICKLING BATHS 5 Sheets-Sheet 3 Filed Jan. 13, 1960 3,942,995 RGLLERS FOR FICKLHQG BATES Bernard George Birkin, Oldham, England, assignor to BTR Industries Limited, London, England, a company of Great Britain Filed Jan. 13, 195i Ser. No. 2,220 Claims priority, application Great Britain Jan. 16, 1959 6 Claims. (Ci. 29116) The invention relates to rollers (herein called pickling rollers) for use in pickling baths to carry strip steel or other metal through a pickling acid or other corrosive liquid. Such pickling rollers are commonly submerged, or partly submerged, in the liquid and the metal strip passes downwardly from the top of the bath around the underside of the rollers and then upwardly to the top of the bath. When used in this way the rollers are sometimes called ducking rollers. Pickling rollers are sometimes also provided at the top of the bath for example, between successive baths, and the strip may pass over these rollers on its way to and from the bath or baths or between successive baths. When used in this way the rollers are sometimes known as carry-over rollers. Pickling rollers are also used to support the Wet strip at other positions.

As such pickling rollers necessarily come into contact with the corrosive liquid it is important that they are constructed of, or coated with, a corrosion resistant material. A material which is commonly preferred for this purpose is hard rubber (ebonite) although other resistant materials such as some plastics or stainless steel, may be used. Furthermore the shaft or other supporting means for the rollers must also be resistant to corrosion. A common construction is to-have a fixed shaft extending across the bath and to have a sleeve or roll, or several short sleeves or rolls fitted over the shaft and rotatable thereon. The roll or rolls constitute the rotatable support for the strip. The shaft may be of steel with an ebonite covering and the sleeve or sleeves of ebonite. With such a construction, however, substantial local wear of the covering of the shaft occurs and in time the shaft may be exposed to the acid and failure of the shaft occur. t is an object of this invention to provide an improved construction of pickling roller in which the rate of Wear is reduced.

According to the invention a pickling roller comprises a shaft of, or coated with, a corrosion resistant material, a roll or rolls also of, or coated with, corrosion resistant material fitted over the shaft, and rotatable thereon, and bearing rollers or balls of, or coated with, corrosion resistant material between the roll or rolls and the shaft.

In one form of the invention the shaft is of steel coated with hard rubber, or plastic, and the roll or rolls and the bearing rollers may also be of hard rubber or plastic.

The bearing rollers may be retained in place within the roll or rolls by end plates of ebonite or other hard rubber or plastic material and of annular form secured to the roll or rolls. These plates may also act as spacers for the bearing rollers and in that case they may have, at intervals around the annuli, holes or sockets for ends on the bearing rollers of reduced diameter. Alternatively the bearing rollers may be held in internal grooves within the roll or rolls.

Some specific examples of pickling rollers according to the invention, and their manner of use, will now be described with reference to the accompanying drawings, in which:

FIGURE 1 is a diagrammatic illustration of a strip pickling plant,

FIGURE 2 is a view partly in elevation and partly in section of a carry-over roller,

3,942,995 Patented July 1%, 1962 FIGURE 3 is a view, similar to FIGURE 2, of a ducking roller,

FIGURE 4 is a view, also similar to FIGURE 2, of a support roller,

FIGURE 5 is a section through a modified form of sleeve or roll which may be used in the ducking roller of FIGURE 3, and

FIGURE 6 is. an elevation, partly broken away and partly in section, of an alternative form of support roller.

In the pickling plant illustrated in FIGURE 1 a steel strip 10 to be pickled is passed through a succession of pickling baths 11 containing hot sulphuric acid. The strip is taken over support rollers 12 and carry-over rollers 13 and under ducking rollers 14 submerged in the acid.

The. construction of a carry-over roller is shown in FIGURE 2. The roller has a fixed shaft 16 of steel with an adherent sheath 17 of ebonite over the whole of its surface except for the end spigots 16a which are heldin clamps outside the baths. Fitted over the centre portion of sheath 17 there is a renewable sheath, also of ebonite, formed of sections 18, each of L-section, The sections 18 are secured by nuts 19 acting through ebonite tubes 26 and rings 21.

Around each sheath section 18, there is a sleeve or roll 23 also of ebonite, the outer periphery of these rolls constituting the roller surface engaging the strip 10. The rolls 23 have internal grooves 25 in which run bearing rollers 26 of ebonite. These rollers run on the sheath sections 18 in the grooves formed between the flanges 28 of adjacent sections.

If after a period of service the rolls 23 or sections 18 become worn, they can be replaced without replacement of the shaft '16.

The ducking roller shown in FIGURE 3 is of a construction which is in general like that of the carry-over roller described above except that the rolls 23a are constructed of hollow annular mild steel cores 30 covered with ebonite.

The support roller shown in FIGURE 4 is also similar in construction to the carry-over roller described above except that in this case sheath sections are held by split ebonite bushes 32 held in grooves 33 in the shaft.

in order to reduce wear on the periphery of the rolls 23, 23a, they may be provided with tyres 36 of softer,

wear and shock resistant rubber, as shown in FIGURE 5. These tyres may be renewable.

in cases Where the extra cost of renewable sheath sections 18 is not justified, these may be omitted, as shown in FIGURE 6, the bearing rollers 26 then running on the fixed sheath 17. In the construction shown in FIGURE 6 the rolls 23b are located in the axial direction by a step 37 on the sheath and a ring 38 held to the sheath by ebonite set-screws 39.

The invention is not restricted to the details of the above examples but may be practiced within the scope of the claims. For instance, the bearing rollers may be replaced by hearing balls and either the rollers or the balls may be of steel covered with ebonite. Corrosion resistant materials other than ebonite may be used. For instance an equivalent hard plastic such as polytetrafluorethylene may be used or the shaft may be of stainless steel. The bearing rollers or balls may be held in cages, egg. of ebonite. The individual rolls employed in any of the above examples may be replaced by a single sleeve or roll.

I claim:

1. A pickling roller assembly for guiding traveling sheet material Wetted with corrosive liquid, said pickling roller assembly comprising a shafthaving an outer bearing surface of hard corrosion resistant material, roll means including hard corrosion resistant material disposed around said shaft and freely rotatable thereabout, said roll means having a radially outer sheet-supporting surface and having a radially inner bearing surface of hard plastic corrosion resistant material, annular groove means in'one of said bearing surfaces, and bearing means including rotatable bearing elements with outer surfaces of hard plastic corrosion-resistant material between said shaft and said roll means with said bearing elements disposed in said annular groove means inrolling contact With said radially inner bearing surface of the roll means and with said ,outer bearing surface of the shaft to. permit full circle rotation of the roll means about said shaft under the turning forces exerted on the roll means by the traveling sheet material. a

2., A pickling roller assembly for guiding traveling sheet material Wetted with corrosive liquid, said pickling roller assembly comprising a shaft having. sheath means of hard rubber providing an outer bearing surface, a plurality of adjacent side-by-side rolls including hard rubber disposed around said shaft and sheath means with each roll freely rotatable thereabout, each of said rolls having a radially outer sheet-supporting surface and having a radially inner bearing surface of said hard rubber with annular groove means therein, and rotatable bearing elements with outer surfaces ofhard rubber between said sheath means and each of said rolls and disposed in said annular groove means of each roll in rolling contact with said hard rubber bearing surface thereof and with said hard rubber bearing surface of the sheath means to permit full circle rotation of the rolls about said shaft under the turning forces exerted on the rolls by the traveling sheet material.

3. A pickling roller assembly as defined in claim 2 in which said sheath means comprises a first sheath of hard rubber vadhesively united with the material of said shaft and having a substantially smooth cylindrical outer surface, and a removable second sheath of hard rubber mounted telescopically upon said first sheath in sliding fit relation thereto with an outer bearing surface of said 4; hard rubber contacting said bearing elements, and detachable means on said shaft securing said removable second sheath thereto.

4. A pickling roller assembly as defined in claim 2 in which said sheath means comprises a removable sheath of hard rubber having a plurality of individual sections of L-shape in cross-section corresponding in number to the number of said rolls with each section disposed at a roll and having a hard rubber outer bearing surface contacting the said bearing elements disposed in said groove means of the roll, and detachable means on said shaft securing thereto said L-shaped sections arranged in endto-end abutting relation. V

5. A pickling roller assembly as 'defined'in claim 2 in which each of'said rolls consists of hard rubber throughout the radial thickness of the roll wall and in which said groove means of each roll consists of a pair of axially spaced-apart annular grooves in said hard rubber radially inner bearing surface of the roll, and said bearing elements are roller bearing elements in said annular grooves.

6. A pickling roller assembly as defined in claim 2 in which each of said rolls comprises a rigid hollow annulus of steel entirely enclosed within a shell of hard rubber and a tire of resilient wear-resistant rubber about the radially outer periphery of'said hard rubber shell pro viding said sheet-supporting surface of the roll, said shell providing said hard rubber radially inner bearing sur-' face of the roll with said annular groove means therein.

References (lited in the file of this patent UNITED STATES PATENTS 207,313 Smith Aug. 20; 1878 322,570 Wagner July 21, 1885 1,232,053 Lawrence July 3, 1917 2,650,603 Howes Sept. 1, 1953 OTHER REFERENCES ,Nylon Parts for Ball Bearings, Product Engineering. pp. 119-123. Div. 45 Feb. 1952. 

